Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.3.99.3 (acyl-CoA dehydrogenase)
 1,425 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Caffeic acid (CA) is found in a wide variety of foods such as vegetables, fruits, tea, coffee, and wine. However, enzymes involved in its metabolism have not been identified. In the following, caffeic (CA), chlorogenic (CGA), and dihydrocaffeic (DHCA) acids were incubated with hepatocytes and shown to undergo metabolism by cytochrome P450, catechol-O-methyltransferase (COMT), and beta-oxidation enzymes. Ferulic (FA) or dihydroferulic (DHFA) acids, formed as the result of CA- or DHCA-O-methylation by COMT, were also O-demethylated by CYP1A1/2 but not CYP2E1. DHCA or DHFA also underwent side chain dehydrogenation to form CA and FA, respectively, which was prevented by thioglycolic acid, an inhibitor of the beta-oxidation enzyme acyl CoA dehydrogenase. The rates of glutathione conjugate formation catalyzed by NADPH/microsomes (CYP2E1) in decreasing order DHCA>CA>CGA trend which was in reverse order to the rates of their O-methylation by COMT. The CA- and DHCA-o-quinones formed by NADPH/P450 likely inhibited COMT but can readily form glutathione conjugates. CA, DHCA and DHFA were inter-metabolized to each other and to FA by isolated rat hepatocytes whereas FA was metabolized only to CA but not to DHCA or DHFA. CA, DHCA, FA, DHFA and CGA showed a dose-dependent hepatocyte toxicity and the LD(50) (2 h), determined were in decreasing order of effectiveness DHCA>CA>DHFA>CGA>FA. In summary, evidence has been provided that O-methylation, GSH conjugation, hydrogenation and dehydrogenation are involved in the hepatic metabolism of CA and DHCA. The O-methylation pathway for CA and DHCA is a detoxification route whereas o-quinones formation catalyzed by P450 is the toxification route.
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PMID:Metabolism of caffeic acid by isolated rat hepatocytes and subcellular fractions. 1211 22

Increased oxidative/nitrosative stress is a major contributing factor to alcohol-mediated mitochondrial dysfunction. However, which mitochondrial proteins are oxidatively modified under alcohol-induced oxidative/nitrosative stress is poorly understood. The aim of this study was to systematically investigate oxidized and/or S-nitrosylated mitochondrial proteins and to use a biotin-N-maleimide probe to evaluate their inactivation in alcoholic fatty livers of rats. Binge or chronic alcohol exposure significantly elevated nitric oxide, inducible nitric oxide synthase, and ethanol-inducible CYP2E1. The biotin-N-maleimide-labeled oxidized and/or S-nitrosylated mitochondrial proteins from pair-fed controls or alcohol-fed rat livers were subsequently purified with streptavidin-agarose. The overall patterns of oxidized and/or S-nitrosylated proteins resolved by 2-dimensional polyacrylamide gel electrophoresis were very similar in the chronic and binge alcohol treatment groups. Seventy-nine proteins that displayed differential spot intensities from those of control rats were identified by mass spectrometry. These include mitochondrial aldehyde dehydrogenase 2 (ALDH2), ATP synthase, acyl-CoA dehydrogenase, 3-ketoacyl-CoA thiolase, and many proteins involved in chaperone activity, mitochondrial electron transfer, and ion transport. The activity of 3-ketoacyl-CoA thiolase involved in mitochondrial beta-oxidation of fatty acids was significantly inhibited in alcohol-exposed rat livers, consistent with hepatic fat accumulation, as determined by biochemical and histological analyses. Measurement of activity and immunoblot results showed that ALDH2 and ATP synthase were also inhibited through oxidative modification of their cysteine or tyrosine residues in alcoholic fatty livers of rats. In conclusion, our results help to explain the underlying mechanism for mitochondrial dysfunction and increased susceptibility to alcohol-mediated liver damage.
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PMID:Inactivation of oxidized and S-nitrosylated mitochondrial proteins in alcoholic fatty liver of rats. 1705 63